"Basically she wants open borders. She doesn't mind human trafficking or she wouldn't do this," Trump added.

Pelosi has previously backed legislation to fight human trafficking and called it "an abhorrent crime."

A bipartisan House-Senate committee is considering proposals for funding border security measures for the current fiscal year ahead of a deadline in two weeks when stopgap funding ends and a new partial federal shutdown could begin. Pelosi said on Thursday, "There's not going to be any wall money in the legislation" to fund border security for the rest of this year.

'WILD AND PREDICTABLE'

Drew Hammill, a spokesman for Pelosi, in a statement condemned Trump's "wild and predictable misrepresentations about Democrats' commitment to border security."

"Democrats have put forward strong, smart and effective border security solutions in the bipartisan conference committee, while the president still refuses to take a second shutdown off the table," Hammill said.

Under the US Constitution, Congress holds the national purse strings and approves major expenditures of taxpayer funds.

Trump said at a White House event he might declare an emergency because it did not appear Democrats in Congress were moving toward a deal to provide wall money. Such a step likely would prompt a court challenge from Democrats.

"I think there's a good chance that we'll have to do that," Trump added, referring to the possibility of an emergency declaration.

Pelosi has said she was open to negotiating funding for more ports of entry or additional border security technology. She said the 17 House and Senate negotiators working on legislation to fund homeland security for the fiscal year should decide components of border security.

Democratic negotiators unveiled a detailed opening position containing no money for additional physical barriers on the border to control the flow of illegal immigrants and drugs. Previously they had supported $1.3 billion for new fencing and improvements to existing barriers.

Construction of a border wall was one of Trump's signature 2016 campaign promises, and he previously said Mexico would pay for it.